Serco, the private contractor that falsified its NHS data in Cornwall, is looking to pass on its troubled GP out-of-hours service in the county to a subcontractor. The Guardian has learned that Serco has been in talks with the NHS to hand delivery of the service to Devon Doctors, a not-for-profit enterprise run by GPs in neighbouring Devon.

Margaret Hodge, chair of the parliamentary accounts committee (PAC), which held an inquiry into Serco's performance in Cornwall earlier this year, described the move to offload the contract as outrageous.

"It's absurd that the government contracts with one company, which can't cope and misleads us all, and the company then just hands the job over to another. How on earth can you have proper accountability like this?" she said.

Serco's negotiations over subcontracting follow a Guardian investigation which revealed it had falsified its performance data when reporting to the local NHS trust so that it appeared to meet targets in the contract that it failed to achieve.

Clare Gerada, chair of the Royal College of GPs, said subcontracting NHS contracts would lead to a fragmentation of service, which could damage patients' interests.

"Serco hugely underestimated the complexity of out-of-hours provision in bidding for the contract," she said. "Now commissioners are tied up in a contractual and competition nightmare, when the most sensible thing would be to break the contract and invite local doctors to provide the service, which is what they were doing before the existing co-op was dismantled for this contract."

The contract was originally awarded to Serco by the NHS primary care trust for Cornwall. The PAC ruled it had been deeply ineffective in writing and managing the contract and did not impose any penalties when Serco's failings were discovered, instead making bonus payments to the company. Serco was given a further five-year contract in 2012, which has four years still to run.

When the PAC reported, the company volunteered to pay back the bonus payments to the new Kernow clinical commissioning group (CCG), which took over responsibility for Cornwall's services as part of the government's NHS restructuring earlier this year. Under competition rules, the CCG cannot end the contract without re-tendering it, a costly process that could take up to a year.

Dr Chaand Nagpaul, chair of the the British Medical Association's GP committee, said: "The PAC report into the failure of out-of-hours care in Cornwall raised serious concerns about the operation and transparency of contracts with non-NHS providers throughout the NHS.

"Subcontracting out-of-hours services is not the solution and carries with it further risks."

If the subcontracting goes ahead, Serco will remain legally responsible for making sure the terms of the contract are met, and is likely to charge a management fee, although a new provider will be invited to deliver the service.

Neither Serco nor the CCG would comment on proposals for the contract, although both confirmed that they have been in talks. "We have been working with our NHS customer to improve integration of our service with other providers in the region and the NHS is considering a number of options, including the possibility of the clinical elements of Serco's service being delivered by a suitable specialist subcontractor," said Serco's director in Cornwall, Dr Louis Warren.

Devon Doctors also declined to comment. It is a social enterprise providing out-of-hours GP services to Devon, with the majority of its shifts covered by GPs who work for Devon practices. It originally bid for the Cornwall contract and although it beat Serco on other criteria, it lost out on price.